Test-retest variability of high resolution positron emission tomography (PET) imaging of cortical serotonin (5HT2A) receptors in older, healthy adults

Abstract Background Position emission tomography (PET) imaging using [18F]-setoperone to quantify cortical 5-HT2Areceptors has the potential to inform pharmacological treatments for geriatric depression and dementia. Prior reports indicate a significant normal aging effect on serotonin 5HT2Areceptor (5HT2AR) binding potential. The purpose of this study was to assess the test-retest variability of [18F]-setoperone PET with a high resolution scanner (HRRT) for measuring 5HT2AR availability in subjects greater than 60 years old. Methods: Six healthy subjects (age range = 65–78 years) completed two [18F]-setoperone PET scans on two separate occasions 5–16 weeks apart. Results The average difference in the binding potential (BPND) as measured on the two occasions in the frontal and temporal cortical regions ranged between 2 and 12%, with the lowest intraclass correlation coefficient in anterior cingulate regions. Conclusion We conclude that the test-retest variability of [18F]-setoperone PET in elderly subjects is comparable to that of [18F]-setoperone and other 5HT2AR radiotracers in younger subject samples.